The Okavango Delta is seasonal. These so called canals look like rock straitions from a receding glaciar, on a particularly grand scale.
It doesn’t appear that the “researcher” has ever been to the site. It looks like the entirety of his research was done on google earth. I see he complains about geologists so he apparently asked one but didn’t like the answers he got.
I would want many dozens if not hundreds of core samples from the tops of the ridges to the bottoms of the valleys all across the region.
The guy makes global warming science look downright professional.